Spark-gap mechanism



C. J. REED sunk an uncnmlsm l-iled i'eb. 28. 1921 Patented May 5, 1925.

UNITED STATES PATENT oFrIcE.

CHARLES :r. rennin, or sen MATEO, camroanra, ASSIGNOE or ONE-HALF To ALICE A.

HALL, OF SAN FRANCISCO, CALIFORNIA.

SPARK-GAP MECHANISM.

Application filed. February v28, 1921.

To all whom it may concern:

Be it known that I, CHARLES J. REED, a

citizen of the United States, residing at San Mateo, in the county of San Mateo and State of California, have invented certain new and useful Improvements in Spark-Gap Mechanism, of which. the following is a specification.

My invention relates to an improved spark gap mechanism and is particularly applicable to electric circuits used for the ignition of gaseous mixtures in internal combustion engines.

In the past many devices of this character have been proposed. The general object of this invention is to provide a spark gap mechanism of exceedingly simple construction and low cost of manufacture and another object is to provide a mechanism which may be readily applied to an ordinary spark plug without materially changing the latter or the connection to it. I Reference is had to the accompanying drawings which form a part of the specification and in which Fig. 1 is an elevation of a spark plug and connecting wire, embodying the invention;

Fig. 2 is a plan view thereof;

Figs. 3, 4 and 5 are perspective views ofelements forming part of the construction shown in Figs. 1 and 2;

Fig. 6 is a plan view showing the essential relationship of the parts forming the in vention; and

Figs. 7 and 8 are perspective view and i elevation, respectively, of a modified form of the principal part of the invention.

In Figs. 1 and 2, 10 represents an ordinary form of spark plug and 11 an ordinary form of connector for establishing electrical connection from a source of current tothe spark plug. I

Ordinarily the terminal or connector 11 is firmly clamped between the contact surface 12 and a metallic washer 13 of the binding 1 post of the plug by means of a knurled nut 14; and it is not material whether the perforation in the terminal 11 through which the screw-threaded stem 15 passes closely fits the stem15 or not.

In order to apply my invention I make this perforation of such size that an annular gap may be formed between" the stem 15 and the edge of the terminal surrounding it, as clearly indicated in Fig. 6.

Serial No. 448,664.

The invention comprises as essential elements a washer 16 and a washer 17, both of insulating material, between which the terminal is received. The washer 16 has a raised portion 18 adjacent its opening adapt ed to take up the space between the stud 15 and the terminal 11 and to thereby per inanently space the latter from the former. When the terminal 11 is thus clamped between the washe-rs16 and 17 a permanent gap is formed in the circuit in series with the main spark gap at the bottom of the plug.

It is understood that the washers 16 and 17 may have slots extending inwardly from the outer edge similar to the slot in the terminal 11.

To allow the spark to take a definite path, various provisions may be made. As indicated in Figs. 4:, 6 and 7, the upper washer 17 maybe provided with an opening or openings 19. In the particular instance there are three openings to make sure that at least one opening is positioned between the metal of the terminalll and the washer 13. The washer 17 has athickness corresponding to the length of the gap to be formed between t the terminal 11 and the washer 13. In pracmerely in that the two insulating washers are formed in one themselves.

In the claims the term binding post does not refer only to a binding post of the usual kind, but includes any stem-like element whether it is part of another structure or not. c

I claim: l

1. In a spark-gap mechanism, the combination of two thinwashers of insulating material, one of the washers having a turned-up inner edge portion and one of the washers having a perforation intermediate the inner edge and the periphery.

2. In a spark gap mechanism, the combination of two thin insulatin washers, one

piece and folded upon mediate the inner edge and the periphery and the inner edge portion of one of the close proximity to, but insulated from the Washers extending out of the plane of the binding post, said tWo insulating sheets and 10 Washer substantially at right angle thereto. said conducting strip being in the form'of 8. A spark-gap mechanism comprising collars to the binding post, one of said inthe terminals of an electric circuit, one being sulating sheets being perforated to allow a fixed binding post, the other a flattened passage of an electric spark. conducting strip clamped between two sheets In testimony whereof, I aflix my signature. of insulating material, by Which it is held in CHARLES J. REED. 

